Handling petroleum emulsions



Patented Aug 1, 1944 HANDLING PETROLEUM EMULSIONS John I l. Harlan, Houston, Tex.,assiguor to Standard Oil Development Company, a corporation of Delaware No Drawing. Application September 14,1942, Serial No. 458,329

' 13 Claims.

droplets of water or brine dispersed in-amore or less permanent state through the oil which constitutes the continuous phase of the emulsion. The agents heretofore developed have been of varying degrees of efliciency, but all of them have the drawback of being of limited applicability.

'It has now been found that the efliciency of such demulsifying agents, as well as the number of different types of emulsions to which they can be successfully applied, can be increased by making them up b combining difierent definite types of hitherto known agents. More particularly, it has been found that very effective agents can be compounded by combining a Diels-Alder condensation product of a terpene and m'aleic anhydride or acid and a substance which will hereinafter be referred to as a reesterified bodied fatty oil. The first of these agents may be termed a desludger, because it functions especially to break down the sludges which are thrown down from emulsions by agents of the second specified type which, for the purpose of discussion, may be termed sludging agents. Other agents than those specified will act as desludging agents, but with much less efliciency than the particular type specified. Likewise, other agents, such as Diels- Alder condensation products synthesized from fatty acids and fatty oils and maleic anhydride, function as 'sludging agents but, again, with much less efliciency than the specific class named above.

The preparation of the Diels-Alder condensation products from terpenes and maleic acid or anhydride is described in detail in U. S. Patents 1,993,026, 1,993,027, 1,993,028, 1,993,029, 1,993,030, 1,993,032 and 1,993,033. The terpenes employed in the preparation of these products may have conjugated double bonds or be free from such bonds. Typical terpenes which may be employed are alpha-pinene, beta-pinene, dipentene, dand l-limonene, terpinolene, alpha-terpinene, and alphaand beta-phellandrene. The condensation products arep referably employed in the present invention are the ethylene glycol esters of the condensation. products prepared by condensing turpentine and .maleic anhydride. Of the glycol derivatives, those preferred are the diand tri-ethylene glycol derivatives.

When reference is made to a bodied fattyoil there is meant a fatty oil the molecular weight of which has been increased by oxidation or heat polymerization, or both. Thus, the term includes blown castor oil, blown linseed oil, heat bodied linseed oil, and other blown or heat bodied fatty oils which undergo molecular change upon oxidation or heat. For use in the practice of the present invention, these oils are re-esterifled with polyethylene glycols of molecular weights from about 250 to 4,000, depending upon the oil selected. For different oils, difierent polyglycols' are most efiective for re-esteriflcation for the purpose of the present invention. It has been found, for example, that nonaethylene glycol produces the best product with heat-bodied linseed form of esters obtained by reacting the condensation products with monoor polyhydric al- The preferred derivatives for the purpose of the oil. For blown castor oil a'polyglycol of much higher molecular weight, around 2,000, is employed. If desired, a number of different glycols may be used simultaneously in the re-esterification. During the re-esteriflcation it is helpful to employ a minute amount of caustic soda to catalyze the re-esterification. It may be mentioned that the esterification in the case of any of these fatty oils may take place at the same time the oil is being processed to body it, that is to say, the glycols can be mixed with raw linseed oil and the esterification and bodying carried out simultaneously,

The performance of these mixtures in the demulsification of water in oil emulsions is improved by employing conjointly with them an oil soluble petroleum sulfonic acid in.the form of its sodium salt. An oil soluble petroleum sulfonic acid is one which is recovered from the acid oil resulting from the treatment of petroleum oil with concentrated sulfuric acid,'as distnguished from the sulfonic acid, which is recovered from the sludge layer resulting from such a sulfuric acid treatment. A particularly efiec tive petroleum sulfonic acid is one which is obtained by washing the acid oil with a limited amount of water and recovering the sulfonic acid from the wash water by first washing out entrained oil with a light paraflinic solvent, then neutralizing the wash water with caustic and separating the water from the resultin sodium sulfonate by distillation.

The proportions in which these various ingredients are compounded may vary over a wide range, the important factor apparently being the simultaneous presence of the sludging agent and desludging agent. A wide variety of formulae have been employed, depending on the emulsions to be treated. For each type of emulsion it is advisable to experiment with the proportions'of the ingredients in'order, to arriveat the best composition. Ordinarily when-the sulfonate is employed it will constitute the predominant ingreclient. ,For most emulsions the desludging agent', will be used in smaller amounts than the sludging agent. The various ingredients'will mix with each other to form a clearmixture. .Thismixture will usually require some dilution in order to bring it to a viscosity which permits easy handling. Dilutionmay be. accomplished by adding an aromatic solvent, suchfas xylene, benzol, or

aromatic cuts obtained from petroleum. A certain amount of water will also be tolerated in I the mixture. Depending upon the quantity of the sulfonate' employed, ,the water content may range up to about 10%. Of course, it is desirableto use as much water as possible, because the more water employed, the less thinner will be required to.obtain the desired viscosity. Especially when water is included it is advantageous soluble sodium petroleum 'sulfonate, 25% of arcmatic diluent, 20% of Diels-Alder condensation product, and 5% of ammonia water, and the second containing -50% of the sodium sulfonate,

- 25% of the re-esterified bodied oil, 20% ot aromatic diluent and 5% of ammonia in water, and combine the two base mixtures in different proportions. The composition made by blending equal parts of the two'base mixtures might be said to be a fairlyrepresentative treating agent according to the present invention. .As hasbeen indicated, in this'representative treating agent the preferred Diels-Alder condensation product is that obtained by'esterifying withtriethylene glycol the condensation product. of maleic anhysaid to be sludged when the water is thrown down in the form or a sludge or tight emulsion, leaving a supernatent layer of substantially anhydrous oil. A water-in-oil emulsion is said to be desludged when a clear layer of water is thrown down from the emulsion, leaving small particles of water still inthe oil in the form of emulsion. In otherwords, when the emulsion is sludged, clear oil.is recovered from it, while when it is desludged clear water is recovered from it, in each case leaving the other component still inan emulsified state. Thus, a sludging agent is one which will break out oil, while a desludging agent is.- one which will break out water.

It will be understood that the treating agent hereinbefore described is useful also in the dedride with turpentine, and the preferred re-esterified bodied fatty oil is that obtained by com- ,bining' nonaethylene glycol-with heat bodied linseed oil. The lattercornpound' is conveniently iormedby heating linseed oil with nonaethylene glycol for about four hours at 450-480 F.

It will understood that the demulsifying salting of oil. It is, of course, recognized that the water customarily associated with crude oil in the form of a water-in-oil emulsion is brine, so that when the emulsion is demulsified the oil may, in a'sense, be said to be desalted. There is-also in the oil, however, a quantity of salt which apparently exists in the form of minute crystals which is not removed in the demulsifyingoperation and which requires a separate operation, referred to as desalting. This latter operation is ordinarily one in which the oil is washed with hot water and during the operation emulsiontroubles are frequently encountered. It is highly beneficial to add a demulsifying agent of the type hereinbefore described to the wash water in this desalting operation.

There are other operations, both inthe art of producing oil and in the art of refining oil, in

which water-in-oil emulsions are formed. A common operation in which emulsion troubles are encountered is that of acidizing oil-producing formations. In this operation a composite 'treating agent accordingto the present invention may be addedto theacid employed for the acidizing step. 1

The nature and objects of the present invention having been described, what is claimed as new and useful and desired to be secured by Letters Patent is:

l. A method for resolving a water-in-oil emulsionwhich comprises treating it with a composition containing a Diels-Aldercondensation product, derived from a terpene and an open-chain, polycarboxylic unsaturated acid body reactive in the Diels-Alder synthesis, and a bodied fatty oil re-esterified with a polyalkylene glycol.

agents according to the present invention will be used in amounts customarily employed in the art. It may be stated that these composite agents are characterized by effecting a faster, cleaner and more complete break of the oil and water than agents heretofore employed. The composite treating agent is almost universally applicable to emulsions of this type encountered in the field.

A great many'of the emulsions which can be readily resolved will not respond at all to either the desludging or the sludglng agent alone. In

actual figures, ,the amount of treating agent employed maywaryiromjabout one part of treatingagentto 1,000 parts of emulsion, up to about '1, part of treating agent. to 30','000 parts of emul- .Ision. Usually one part of treating agent to 10,-

.000 parts 01 emulsion will'be satisfactory.

' It may be helpful to enlarge slightly upon the meaning of the'expressions sludging agent and desludging agent. Awater-in-oil emulsion is 2. A method for resolving a water-i'n-oil emulsion which comprises treating it with a composition containing a Diels-Alder condensation product, derived from a terpene hydrocarbon and maleic acid, and a bodied fatty oil re-esterifled with a. polyalkylene glycol.

sion which comprises treating it with a compositioncontaining an ester derivative of a Diels- Alder condensation product, derived from a terpene and maleic acid, and a bodied fatty oil reesterified witha polyalkylene glycol.

4. A method for resolving a water-in-oil emulsion which comprises treating it with a composition containing a Diels-Alder condensation product, derived from a terpene and a polycarboxylic unsaturated open-chain acid reactive in the Diels- Alder synthesis, a bodied fatty oilreesterifled with a polyalkylene glycol and an oil soluble petroleum sulfonic acid. Q

5. A method for resolving a water-in-oil emulsion which comprises treating it with a composi- 3. A method for resolving a'water-in-oil emultion containing a Diels-Alder condensation product, derived from a terpene and a malelc acld body, a bodied fatty oil re-esterifled with a polyethylene glycol and a salt of an oil soluble petroleum sulfonic acid.

6. A composition of matter for' use as a demulsifler comprising a Diels-Alder condensation product of a terpene and an open-chain polycarboxylic unsaturated acid body reactive in the Diels-Alder synthesis and a bodied fatty oil reesterifled with a'polyalkylene glycol.

7. A composition of matter for demulsifying purposes comprising an ester of a Diels-Aldercondensation product, derived from a terpene and an open-chain polycarboxvllc unsaturated acid body reactive in the Diels-Aider synthesis'and a bodied fatty oil re-esterifled with a poiyaikylene glycol.

8. A composition of' matter for demulsifylng purposes comprising a Diels-Alder condensation product, derived from a terpene and an openchain unsaturated polycarboxylic acid reactive in the Diels-Alder synthesis, a bodied fatty oil re-esterifled with a polyalkylene glycol and an oil soluble petroleum sulfonic acid body.

oil is a heat bodied linseed oil re-esterified with" 9. A composition of matter for demulsifylng purposes comprising an ester of a Diels-Alder condensation product, derived from a terpene and a maieic acid body. a bodied fatty oil reesterifled with a polyalkylene glycol and a salt of an oil soluble petroleum sulfonlc acid.

10. A composition according to claim 9 in which the re-esterifled fattyoil is a heat bodied linseed oil re-esterified-with a polyethylene glycol.

11. A composition according to claim 9 in which the ester of the Diels-Alder condensation product is a glycol ester and the re-esterifled bodied fatty nonaethylene glycol.

12. A method according to claim 1 ii; which 5 the re-esterifled fatty oil is a heat bodied linseed oil re-esterified with a polyethylene glycol.

13. A method according to claim 3 in which the ester derivative of the Diels-Alder condensation product is a glycol ester and the re-esterifled bodied fatty oil is a heat bodied linseed oil reesterifled with nonaethyiene glycol.

JOHN L. HARLAN. 

